US and UK cybersecurity and law enforcement agencies today shared information on new malware deployed by the Iranian-backed MuddyWatter hacking group in attacks targeting critical infrastructure worldwide.
This was revealed today in a joint advisory issued by CISA, the Federal Bureau of Investigation (FBI), the US Cyber Command's Cyber National Mission Force (CNMF), UK's National Cyber Security Centre (NCSC-UK), and the National Security Agency (NSA).
MuddyWater is "targeting a range of government and private-sector organizations across sectors—including telecommunications, defense, local government, and oil and natural gas—in Asia, Africa, Europe, and North America," the two governments
said.
This threat group uses multiple malware strains—including PowGoop, Canopy/Starwhale, Mori, POWERSTATS, as well as previously unknown ones—to deploy second-stage malware on compromised systems, for backdoor access, to maintain persistence, and for data exfiltration.
Among the malware detailed today, the US and UK agencies highlighted a new Python backdoor (dubbed
Small Sieve) used by MuddyWater operators for persistence and a PowerShell backdoor used to encrypt command-and-control (C2) communication channels.
"Small Sieve provides basic functionality required to maintain and expand a foothold in victim infrastructure and avoid detection by using custom string and traffic obfuscation schemes together with the Telegram Bot application programming interface (API),"
the advisory reads.